I use screen; for one, if I lose the connection, I can resume it. As for KDE, it's a bit too newbieish and Windows 95 for my liking. Though aRts is pretty nifty for extracting audio from applications' output.
What is needed is a way of interfacing screen with the tabs; perhaps have them send ^A 1 or whatever. Though you'd want some sort of channel back to the terminal app.
Eterm's supposed to have some kind of interface to Screen in the latest release, but I haven't given it much of a go...
...I'm just trying it again - it seems to put tabs along the bottom for each of your 'screens', yeah.
yeah. KDE's had it in their terminal for ages - it's vaguely handy, but nothing like Screen.
http://www.math.fu-berlin.de/~guckes/screen/